Clear viewseal sealer

Measurements were carried out on several microplate readers (Tecan SAFIRE, Tecan, Switzerland; LB 943 Mithras², Berthold, Germany; Synergy H1, BioTek, United States) at 25 °C. UV–vis spectra were recorded using a 96-well plate (transparent, polystyrene, flat bottom, Sarstedt, Germany) as sample holder with clear viewseal sealer (Greiner Bio-One, Austria). The spectra were obtained in the wavelength range from 340 nm to 500 nm or 800 nm for the hydrogels that release 4-nitrophenol or 5,5′dibromo-4,4′-dichloro-indigo, respectively. A 1 nm wavelength step size was using for the Tecan SAFIRE for enzyme detection and the LB 943 Mithras² performing the E. coli DH5α strain detection, and a 2 nm was used for the Synergy H1 for the EHEC strain detection, respectively.

Measurements were carried out either with a Varian Cary Eclipse spectrometer (Mulgrave, Victoria, Australia) or with microplate readers (Tecan SAFIRE, Tecan, Switzerland or LB 943 Mithras², Berthold, Germany) at 25 °C. Fluorescence spectra obtained with the Varian Cary Eclipse spectrometer were measured at a scan rate of 120 nm/min and a resolution of 5 nm for the excitation and emission, using a 1 mm path-length quartz cell (SUPRASIL, Hellma Analytics, Germany). Fluorescence intensity measurements, which were recorded on the microplate reader, were performed using 96-well plates (black, polystyrene, flat bottom, Sarstedt, Germany) as sample holder with clear viewseal sealer (Greiner Bio-One, Austria). A bandwidth of 12 nm was applied for both excitation and emission. The gain parameter was manually set to 70 for the Tecan SAFIRE and to 255 for the LB 943 Mithras², respectively.